Sealing multiple surgical instruments

ABSTRACT

A cannula cap is disclosed. A cannula cap according to some embodiments of the invention includes an instrument guide attachment; a cannula attachment; and a seal captured between the instrument guide attachment and the cannula attachment. In some embodiments, a cannula cap can include a lid; a locking ring; a base; and a cannula seal captured between the lid and the base.

RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 14/211,713,filed on Mar. 14, 2014, which claims priority under 35 U.S.C. § 119(e)to U.S. Provisional patent Application Ser. No. 61/801,081, filed onMar. 15, 2013, each of which is herein incorporated by reference in itsentirety.

BACKGROUND Technical Field

Embodiments of the present invention are related to teleoperated roboticsurgery and, in particular, to sealing multiple surgical instruments ina single cannula.

Discussion of Related Art

Minimally invasive surgery (MIS) (e.g., endoscopy, laparoscopy,thoracoscopy, cystoscopy, and the like) allows a patient to be operatedupon through small incisions by using a camera and one or more elongatedsurgical instruments introduced to an internal surgical site. Thesurgical site often comprises a body cavity, such as the patient'sabdomen. The body cavity may optionally be distended using a clear fluidsuch as an insufflation gas, typically CO₂. In traditional minimallyinvasive surgery, the surgeon manipulates the tissues by usinghand-actuated end effectors of the elongated surgical instruments whileviewing the surgical site on a video monitor.

One or more cannulas may be passed through small (generally 7 cm orless) incisions or a natural body orifice to provide entry ports for theminimally invasive (e.g., endoscopic, laparoscopic, and the like)surgical instruments, including a camera instrument (e.g., endoscope,laparoscope, and the like). A surgeon is able to perform surgery bymanipulating the surgical instruments from outside the body whileviewing the instrument end effectors at the internal surgical site withimages provided by the camera instrument.

It is typical to provide several cannulas for a minimally invasivesurgical procedure. Generally, each cannula will provide access to thesurgical site for a single surgical or camera instrument. For example,four cannulas may be provided with one cannula being used to introduce acamera instrument and the remaining three cannulas being used tointroduce surgical instruments, The use of two or more separate entrypoints to access a surgical site may be considered “multi-port”minimally invasive surgery. While the small incisions necessary forplacing a cannula are less traumatic than the incision necessary foropen surgery, each incision still represents a trauma to the patient.

In an effort to reduce the trauma of minimally invasive surgery evenfurther, techniques are being developed to allow minimally invasivesurgery using only a single access port into the body, such as a singleincision or single natural body orifice. This access may be accomplishedby using a somewhat larger cannula that can accommodate all of theinstruments required for the surgery. Minimally invasive surgeryperformed through a single incision or natural orifice may be referredto as single port access (SPA) surgery. The single cannula that providesthe single port may be introduced through a body orifice or through anincision.

If multiple surgical instruments and/or camera instruments are to beintroduced to a surgical site through a single cannula, it can becomedifficult to manage the instruments within the cannula. It is desirableto use as small a cannula as possible, consistent with the size of theinstruments to be passed through the cannula. This may make it difficultto introduce the necessary instruments and to maintain the necessarymobility of the instruments as well as to prevent the insufflation gasfrom escaping via the access port as various instruments are insertedand removed from the cannula, as well as during instrument use duringsurgery.

Therefore, there is a need to develop systems for better and moreeffective access to the surgical area.

SUMMARY

In accordance with aspects of the present invention, a cannula cap isprovided. A cannula cap according to some embodiments of the inventionincludes an instrument guide attachment; a cannula attachment; and aseal captured between the instrument guide attachment and the cannulaattachment.

In some embodiments, a cannula cap can include a lid; a locking ring; abase; and a cannula seal captured between the lid and the base.

These and other embodiments are further discussed below with respect othe following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates components of a single-port teleoperated roboticsurgical system.

FIGS. 2A, 2B, 2C, and 2D illustrate an access port according to someembodiments of the present invention.

FIGS. 3A and 3B illustrate utilization of an obturator according to someembodiments of the present invention.

FIG. 4A illustrates a cannula cap according to some embodiments of thepresent invention.

FIGS. 4B-4E illustrate aspects of some embodiments of a cross-slit sealthat can be used with many cannulas.

FIGS. 4F-4J illustrate some embodiments of a cross-slit seal that can beutilized with many cannulas.

FIGS. 4K-4O illustrate some embodiments of a cross-slit seal that can beutilized with many cannulas.

FIGS. 4P-4R illustrate embodiments of an assembled cannula cap and sealas illustrated in FIG. 4D.

FIGS. 4S and 4T illustrate insertion of an assembled cannula cap andseal into a cannula.

FIGS. 4U and 4V illustrate cross sections of a cannula with insertedcannula cap and seal according to some embodiments of the presentinvention.

FIG. 5A illustrates an instrument guide coupled with a cap according tosome embodiments of the present invention.

FIGS. 5B-5E illustrate an instrument guide according to some embodimentsof the present invention.

FIGS. 6A and 6B illustrate cross sections of embodiments of a channelportion of the instrument guide.

FIGS. 7A and 7B illustrate an instrument seal according to someembodiments of the present invention,

FIGS. 7C, 7D, and 7E illustrate an instrument seal as shown in FIG. 7Aand certain cross sections of that instrument seal.

FIGS. 7F and 7G illustrate top and bottom perspective views of aninstrument seal as shown in FIG. 7A.

FIGS. 7H and 7I illustrate an embodiment of an instrument seal.

FIGS. 7J and 7K illustrate another embodiment of an instrument seal.

FIGS. 7L and 7M illustrate another embodiment of an instrument seal.

FIGS. 7N and 7O illustrate another embodiment of an instrument seal.

FIGS. 8A-8D illustrate a door mechanism according to some embodiments ofthe present invention.

FIGS. 9A and 9B illustrate the relationship between seal angle and dooropening angle in doors according to some embodiments of the presentinvention.

FIGS. 9C and 9D illustrate the embodiments of FIGS. 9A and 9B with thedoors in the closed position.

FIGS. 10A and 10B illustrate the interaction of a surgical instrumentwith the door mechanisms illustrated in FIGS. 9C and 9D, respectively.

DETAILED DESCRIPTION

In the following description, specific details are set forth describingsome embodiments of the present invention. It will be apparent, however,to one skilled in the art that some embodiments may be practiced withoutsome or all of these specific details. The specific embodimentsdisclosed herein are meant to be illustrative but not limiting. Oneskilled in the art will realize other elements that, although notspecifically described here, are within the scope and the spirit of thisdisclosure. In addition, to avoid unnecessary repetition in thefollowing description, one or more features shown and described inassociation with one embodiment may be incorporated into otherembodiments unless specifically described otherwise, unless the one ormore features would make an embodiment non-functional, or unless two ormore of the features provide conflicting functions.

Further, this description's terminology is not intended to limit thescope of the invention, For example, spatially relative terms such as“beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”,“horizontal”, “vertical” and the like may be used to describe oneelement's or feature's relationship to another element or feature asillustrated in the figures. These spatially relative terms are intendedto encompass different positions and orientations of the device in useor operation in addition to the position and orientation shown in thefigures. For example, if the device in the figures is turned over,elements described as “below” or “beneath” other elements or featureswould then be “above” or “over” the other elements or features. Thus,the exemplary term “below” can encompass both positions and orientationsof above and below. The device may be otherwise oriented (rotated 90degrees or at other orientations), and the spatially relativedescriptors used herein interpreted accordingly. Likewise, descriptionsof movement along and around various axes include various special devicepositions and orientations. In addition, the singular forms “a”, “an”,and. “the” are intended to include the plural forms as well, unless thecontext indicates otherwise. And, the terms “comprises”, “comprising”,“includes”, and the like specify the presence of stated features, steps,operations, elements, and/or components but do not preclude the presenceor addition of one or more other features, steps, operations, elements,components, and/or groups. Components described as coupled may beelectrically or mechanically directly coupled, or they may be indirectlycoupled via one or more intermediate components.

FIG. 1 shows a pictorial view of a minimally invasive surgery on apatient 110 using single access port 100 for teleorobotic surgicalinstruments 102, 104, 106. Single access port 100 is inserted through asingle incision 112. Typically three or four surgical instruments(instruments 102, 104, and 106 are illustrated), including a camerainstrument, are introduced through single access port 100. In addition,there will generally be provisions for introducing an insufflation gas,such as carbon dioxide (CO₂), at or near single access port 100. It willbe appreciated that single port surgery utilizes a substantial amount ofequipment located in a small amount of space.

The teleorobotic surgical instruments 102, 104, and 106, which mayinclude a camera instrument that may provide images of the surgical siteand other instruments at the surgical site, are each coupled to acorresponding actuator, such as one of actuators 122, 124, 126, and 128.Actuators 122, 124, 126, and 128 are servo actuators that allow asurgeon to manipulate the surgical instruments using a computer-mediatedcontrol station 120 and are mounted on teleoperated robot 140. Thesemanipulations may include functions such as changing the position andorientation of the surgical instrument's end effector (to include acamera) and operating the end effector (such as closing jaws to effectgrasping, cutting, etc.). Such actuator control of surgical instrumentsmay be referred to by various terms, such as robotic surgery ortelerobotics. Actuators 122, 124, 126, and 128 of teleoperated robot 140may be supported on a separate structural arm that, once positioned, canbe fixed relative to patient 110. In various implementations thesupporting robot arm may be manually positioned, may be positioned bythe surgeon, or may be automatically positioned by the system as thesurgeon moves one or more of the surgical instruments. U.S. patentapplication Ser. No. 12/855,452 (filed Aug. 12, 2010; published as US2011/0282358 A1), incorporated herein by reference, shows additionalillustrative aspects of a single port robotic surgical system.

A control system couples a computer-mediated control station 120 to therobotic actuators 122, 124, 126, and 128. Here “computer” broadlyencompasses a data processing unit that incorporates a memory and anadditive or logical function, such as an arithmetic logic unit, that isprogrammable to perform arithmetic or logical operations. The controlsystem may coordinate movement of the input devices with the movement oftheir associated surgical instruments so that the images of the surgicalinstruments 102, 104, 106, as displayed to the surgeon, appear at leastsubstantially connected to the input devices in the hands of thesurgeon. Further levels of connection will also often be provided toenhance the surgeon's dexterity and ease of use of the surgicalinstruments 102, 104, and 106.

The computer-mediated control station 120 may provide hand operatedmaster controllers 130 that allow manipulation of the teleorobotic slavesurgical instruments 102, 104, 106 by transmitting signals, such aselectrical or optical control signals provided by cables 132, to theactuators 122, 124, 126, and 128 that control the actions of the coupledsurgical instruments 102, 104, and 106. Typically one of the surgicalinstruments, surgical instrument 102 for example, will be a camerainstrument that is manipulated to place the remaining surgicalinstruments and the objects being manipulated within a field of view ofthe camera. The camera instrument transmits signals to the controlstation 120 so that an image captured by the camera of the instrumentsand objects within the field of view can be displayed on a visualdisplay 134 that is viewed by the surgeon as the coupled surgicalinstruments 104, 106 are manipulated. The hand-operated controllers 130and the visual display 134 may be arranged to provide an intuitivecontrol of the surgical instruments 104, 106, in which the instrumentsmove in a manner similar to the operator's hand movements with thecontrollers.

FIGS. 2A, 2B, 2C, and 2D illustrate general aspects of an access port100 that can be inserted through incision 112 according to someembodiments of the present invention. Access port 100 provides thesingle port access as shown in FIG. 1. Access port 100 includes acannula 202 and an instrument guide 204 that is inserted into cannula202. Cannula 202 can include a latch feature 212 (either an object heldby a latch or a latch itself) so that access port 100 can be coupled toteleoperated robot 140 or other holder.

Instrument guide 204 guides multiple instruments through cannula 202 tofacilitate multiple instrument single port access. As illustrated inFIG. 2B, instrument guide 204 includes a channel portion 208 and afunnel portion 206. Instrument guide 204 may be coupled to cannula 202in various ways. For example, as further illustrated in FIG. 2B, acannula cap 210 can be snapped onto cannula 202, and channel portion 208is inserted through cannula cap 210 so that funnel portion 206 snapsonto cannula cap 210. Cannula cap 210 may be omitted in someembodiments, and instrument guide 204 is mated directly with cannula202.

Funnel portion 206 guides instruments into channel portion 208, Channelportion 208 can include four illustrative instrument channels (which maybe termed “lumens”) through which instruments are guided from themanipulator towards the surgical site. Accordingly, funnel portion 206is divided into four funnel guides, each funnel guide corresponding toan associated instrument channel. FIG. 2C is a top view into funnelportion 206, and it illustrates funnel guides 222, 224, 226, and 228that direct instruments into corresponding channels of channel portion208. It can be seen that funnel guides 222, 224, 226, and 228 areseparated from one another by walls 229, and as shown in FIGS. 2A, 2B,and 2D the top edges 229 a of these separating walls extend proximallyfrom instrument guide 204 (they are shown as convex). This extensionhelps to guide an instrument into the proper one of funnel guides 222,224, 226, or 228 during instrument insertion and mounting to theteleoperated robot 140. The instrument channels may be sized and shapedto accommodate various different instruments, and so FIG. 2C also showsthat one funnel guide, funnel guide 222, is larger with a differentcross-sectional shape than the other funnel guides, funnel guides 224,226, and 228, to receive a relatively larger instrument such as, forexample, camera surgical instrument 102.

Channel portion 208 is configured to fit closely within cannula 202.Each of the channels of channel portion 208 is configured to support asingle one of the surgical instruments at a defined position withincannula 202. The surgical instruments are inserted into the access port100 through funnel portion 206 so that they are directed into thechannels at a proximal end of the instrument guide 204, The surgicalinstruments are supported by the channels until they emerge from adistal end of the instrument guide 204. Instrument guide 204 may beformed from an electrically non-conductive material to aid inelectrically isolating the instruments, which may carry an electricalcharge used for electrosurgical applications cauterization

Cap 210 provides a general insufflation seal for cannula 202, asdiscussed in detail below. In alternative embodiments, such aninsufflation seal may be removably or permanently mounted in cannula202, and items to be inserted into and held within cannula 202 arecoupled directly to cannula 202 instead of using a cap. The cap providesan easy way of quickly mounting and removing a seal to the cannula,which can have an inner diameter on the order of 25 mm significantlylarger than current multi-port cannula inner diameters, which range fromabout 5 mm to 13 film and provides mounting features for the itemsinserted with the cannula.

As shown in FIG. 2B, a kit 214 can be formed of cap 210 and instrumentguide 204. In some embodiments, cannula 202 can be reusable (e.g., aftercleaning and sterilization). The components of kit 214 can be sold as asterile kit, e.g., a gamma sterilized kit, so that a new instrumentguide 204 and a new cap 210 may be used for each surgical procedure.

The cannula cap 210 snaps onto the cannula 202, and the instrument guide204 snaps into cap 210. Alternatively, as discussed below, an obturator302 (FIG. 3A) or other device to be inserted into and held withincannula 202 can snap onto cap 210 in a similar way. The individualpieces that make up cannula cap 210 or instrument guide 204 can be fullyassembled during manufacturing, typically not by the user. The assemblymethod may include the use of permanent snaps, gluing, fasteners, heatstaking, ultrasonic welding, or any other attachment method. Details ofthe cap design and instrument guide design are discussed in more detailbelow.

FIGS. 3A and 3B illustrate an example in which an obturator 302 isinserted through cap 210. FIG. 3A illustrates cannula 202 with cap 210and obturator 302. FIG. 3B illustrates cannula 202, cap 210, andobturator 302 assembled. Once cannula 202 has been established inincision 112, obturator 302 can be removed and replaced with instrumentguide 204, as is illustrated in FIGS. 2A and 2D. As explained below, aseal in cap 210 preserves insufflation pressure at the surgical site bypreventing insufflation gas from escaping through cannula 202. Obturator302 may be made to be usable for many surgical procedures, or it may bemade for use during a single surgical procedure (i.e., “disposable”). Ifmade for use during a single procedure, a sterilized obturator 302(e.g., gamma sterilized) may be included in sterile kit 214.

As shown in FIGS. 2A through 2D and in FIGS. 3A and 3B, cap 210 canfasten into cannula 202 and be fixed in place. Further, instrument guide204 or obturator 302 fasten into cap 210. A release mechanism, either oncap 210 or on the inserted object (instrument guide 204 or obturator302) can allow for the removal of instrument guide 204 or obturator 302from the cannula 202 and cap 210 combination. In some embodiments, cap210 allows instrument guide 204 to rotate inside cannula 202. In someembodiments, single port 100 may not include a cap 210.

Cannula Cap and Seal

A cap 210 is illustrated, for example, in FIGS. 2A and 2B. shown, cap210 can be releasably attached to cannula 202 and releasably attached toinstrument guide 204. The cap 210 also positions a cannula seal withrespect to instrument guide 204 and cannula 202. FIG. 4A illustratessome embodiments of cap 210. FIG. 4A illustrates an embodiment of a cap210 that has been disassembled. As shown in FIG. 4A, cap 210 includes alid 402, a locking ring 404, a base 406, and a seal 408. In someembodiments, cap 210 can be formed by mechanically assembling lid 402,locking ring 404, base 406, and seal 408. Assembly (for example, duringmanufacturing) can be performed without glue, and the parts may beconfigured as shown to snap together to form cap 210.

As is further illustrated in FIG. 4A, lid 402 includes an instrumentguide clip 418. Clip 418 can engage instrument guide 204 to mechanicallyfasten instrument guide 204 to cap 210, while allowing instrument guide204 to rotate relative to cannula 202. Such rotation allows the entirecluster of instruments inserted through the instrument guide to rotateas a unit inside cannula 202. Instrument guide clip 418 can also engagereceiver 420 on base 406, which helps hold the cap components together.

Locking ring 404 may include a release mechanism 416, which may includea spring 422. Engagement and release mechanism 416 may extend throughopenings 424 in lid 402 to provide for user release of the cap from thecannula. Engagement and release mechanism 416 also extends throughopenings 440 in base 406 to hold cap 210 onto cannula 202. The latchingtabs 419 are angled so that as the cap 210 is pressed onto cannula 202,locking ring 404 rotates against spring 422 to allow the latching tabsto engage cannula 202, and spring 422 then returns locking ring 404 to alatched position against cannula 202.

Base 406 includes alignment pins 426 that help position cap 210 withrespect to cannula 202 so that cap 210 is correctly oriented on cannula202, In addition, varying quantity or position of alignment pins 426 maybe used (three are shown; one individual and two close together) to keya cannula cap 210 to a specific configuration of cannula 202, forexample, a specific length cannula in a set of cannulas each havingdifferent lengths. Thus a cap improperly configured for a certaincannula is prevented from being latched to such a cannula.

It can be seen that clip 418 on lid 402 releasably engages instrumentguide 204, and locking ring 404 releasably engages cannula 202, so thatcap 210 holds instrument guide 204 inside cannula 202 and also allowsinstrument guide 204 to rotate around its longitudinal (long) axisinside cannula 202, Seal 408 is captured between base 406 and lid 402.

FIGS. 4B, 4C, 4D, and 4E illustrate aspects of a cross slit seal 408that can be used with some cannulas 202, with or without a cap 210. Asshown in FIG. 4B, seal 408 includes a sidewall 428, and sidewall 428includes four sets of inward folded sidewall panels 430. Each set ofsidewall panels 430 intersect one another along panel intersection line431, and all sidewall panels 430 meet at their ends to form cross slits410. The ends of the folded sidewall panels 430 come together to formthe cross slits 410 in a narrow end surface 485 formed by the ends ofthe folded sidewall panels 430.

As shown in FIG. 4C, a height of seal 408 can be defined in alongitudinal direction (aligned between top and bottom) betweenlocations on the outer perimeter of seal 408 at which the foldedsidewall panels 430 begin and the most distant location on end surfaces485. The height shown in FIG. 4C is for the seal 408 when closed, withno instrument or device inserted.

In accordance with some embodiments of the invention, the end surfaces485 are concave (they are shown as a continuous curve but other shapesmay be used) when the cross slits 410 are closed. As shown in FIG. 4E,it can be seen that when an object is inserted through the cross slits410, the folded sidewall panels 430 move away from each other. It canfurther be seen that the innermost ends 485 a of the folded sidewallpanels 430, the locations at which the folded sidewall panels 430contact the object inserted through the slits, are displaced generallyupward as the folded sidewalls 430 move outward. Thus the overall heightof the cross slit seal 408 increases when an object is inserted. Byforming end surfaces 485 to be concave, however, the increase in sealheight that results from the inserted object is reduced.

It can also be seen from FIGS. 4C and 4E, that the sidewall 428 tends tomove outward when an object is inserted through the slits 410, and bytapering the outer diameter of the seal to be narrow towards slits 410,the outer shoulders 485 b of the surfaces 485 can be kept from movingbeyond an overall diameter of the closed seal 408.

As shown in FIG. 4C, a slit length can be defined in a lateral direction(aligned from side to side). As an aspect ratio between the seal heightand slit length changes with the slit length becoming relatively longerwith reference to the seal height, it can be seen that by making endsurfaces 485 concave, the increase in seal height with an insertedobject is reduced relatively more than the increase in seal height ifthe end surfaces 485 were not concave. Thus, the seal will be relativelyshorter with an inserted object, which keeps the seal from interferingwith another longitudinally positioned object and allows an assemblythat allows seal 408 to be relatively shorter. This seal heightreduction allows the associated configurations of cannula 202 and cap210 to be similarly shortened, described more fully below. In minimallyinvasive surgery, even a small change in length (e.g., 1 to 2 mm) can beclinically significant.

As illustrated in FIG. 4D, the large areas of folded sidewall panels 430allows pressure P outside seal 408, for example from insufflation, topush slits 410 closed and keep them closed. A large height in relationto slit length provides for seal 408 to be flexible in the region ofslits 410 so that relatively low pressures can effectively close seal408

In some embodiments of the invention, the outer surfaces 430 a of thefolded sidewall panels 430 are concave. As shown in FIG. 4D, thisconcave shape assists sealing by allowing pressure against the surfaces430 a towards the outer perimeter of seal 408 to be more nearly alignedwith the seal's longitudinal axis, which helps to close the foldedsidewall panels 430 against each other, and by allowing pressure againstthe surfaces 430 a near the center of the seal to be more nearly alignedacross the slits when the seal is closed, which helps to keep the slitsclosed when no object is inserted. This curved sidewall panel surfaceespecially helps to close and keep closed the seals 408 havingrelatively low seal height to slit length aspect ratios (see e.g., FIG.4H), which are described in more detail below.

As shown in FIG. 4A, in some embodiments seal 408 is captured betweenlid 402 and base 406. Locking ring 404 can be separately capturedbetween lid 402 and base 406. In some embodiments, seal 408 asillustrated in FIGS. 4B through 4E may be used without a cap 210 byplacing directly in a cannula. However, the embodiment of seal 408illustrated in FIGS. 4B through 4E may have a higher aspect ratio (ratioof seal height to slit length) than is desired for a particular cannula.FIGS. 4F through 4O illustrate embodiments of seal 408 that can be usedwith cap 210 and that have low seal height to slit length aspect ratios.

As shown in FIGS. 4F-4H, seal 408 includes cross slits 410 and includesgenerally the features that were illustrated in seal 408 in FIGS. 4Bthrough 4E. Folded sidewall panels 430 intersect to form slits 410. Asillustrated in FIG. 4G, a height can be defined by either of sidewall428 (for an overall height of seal 408) or folded sidewall panels 430(for a height of the cross slit seal portion of seal 408), and a slitlength is defined by the length of slits 410. In the FIG. 4G depiction,the height to slit length aspect ratio is less than about 1:1, and moreexactly it is about 1:2. Other aspect ratios less than 1:1 may be used.As described above, the end surfaces 485 in which slits 410 are definedcan be concave in order to shorten the seal height with an insertedobject. Some embodiments of seal 408 have a slit length larger than theseal height, resulting in shorter folded sidewall panels 430 than thatillustrated in embodiments of seal 408 illustrated in FIGS. 4B through4E. This shortened folded sidewall 430 provides for a small area foroutside pressure P to push slits 410 closed, as illustrated in FIG. 4.Additionally, the shortened height and consequent aspect ratio mayresult in a requirement that the sidewall panels 430 of seal 408 bestiffer to maintain proper shape, and so a high pressure P is needed tosufficiently seal the cross slits closed, as is illustrated in FIG. 4I.

FIG. 4J illustrates an embodiment of seal 408 that includes energizingribs 414 that can provide force F from interaction with the inner wallof cannula 202 to help close slits 410 and keep them closed. Thus ribs414 work together with the outside pressure P to close seal 408. Asshown, ribs 414 are formed on the sidewall of seal 408, and in thedepicted embodiment each rib is generally aligned with an outer end ofone of slits 410 so that force from opposing ribs helps to close thecorresponding perpendicular slits 410. FIG. 4H shows a cross section ofseal 408 and illustrates sealing of slits 410 with concave foldedsidewalk 430, as described above. FIGS. 4F-4J also illustrate taperingthe cross slit seal outer diameter towards slits 410 to reduce heightwhen open, as described above.

Ribs 414 shown in FIG. 4J help to compensate for potential reducedsealing performance due to the shortened height relative to slit lengthas compared to seal 408 illustrated in FIGS. 4B-4E. The shortened heightof seal 408 can enable the use of a shorter cannula 202 and resultinglyshorter surgical instruments 102, 104, 106. Shorter surgical instruments102, 104, 106 can be easier to clean and package, and can have improvedstiffness for better surgical performance. Shorter surgical instruments102, 104, 106 and shorter cannula 202 can also enable the use of asmaller teleoperated robot 140.

FIGS. 4K through 40 illustrate various features that may be found,separately or combined, in some embodiments of seal 408, FIG. 4Killustrates a seal with a flange 432 that can be used to hold seal 408in place during installation in cap 210 (or in cannula 202). FIG. 4Lillustrates a seal 408 with an integrated inner diaphragm (also known asa lip or septum type) seal 434 that seals against instrument guide 204.FIG. 4M illustrates a seal 408 with an outer seal 436 that seals againstthe inner wall of cannula 202. FIG. 4M shows outer seal 436 as twoannular lip seals and is illustrative of embodiments in which one ormore various types of seals may be used to seal against a cannula. FIG.4N illustrates a seal 408 with both an inner seal 434 and an outer seal436 so that enhanced seal performance between both a cannula and aninserted object inserted in the cannula is obtained.

FIG. 4O illustrates a perspective of an embodiment of seal 408. As shownin FIG. 4O, seal 408 includes slits 410, sidewalls 428, and foldedsidewall panels 430, energizing ribs 414, flange 432, and outer seal436. The end surfaces at the cross slits are made concave so that withan object inserted the seal height is less than it would be if the endsurfaces were straight across. The concave outer surface of the sidewallpanels 430 helps to direct the fluid pressure vector to move thesidewall panels to the closed position and to keep them closed againsteach other at the cross slits. And, the ribs 414 further help keep thecross slits closed with the stiff sidewall panels required to form thelow height to slit length aspect ratio seal.

FIG. 4P illustrates an assembled cap 210 according to some embodiments.As shown in FIG. 4P, engagement and release mechanism 416 includes abutton that extends through openings 424 in lid 402 and latch tabs thatextend through openings 440 in base 406 and catch against correspondingmating features in the cannula. Seal 408, with slits 410 and energizingribs 414, is captured between base 406 and lid 402. FIG. 4Q illustratesa cross section plan view from the top of seal 408 and illustratesspring 422 and the inclusion of locking ring 404. FIG. 4R illustrates aside view and illustrates pins 426.

Therefore, FIGS. 4P, 4Q, and 4R illustrate different views of assembledcap 210. As is illustrated, seal 408 can be a cross-slit seal with slits410. Further, seal 408 can include energizing ribs 414. Engagement andrelease mechanism 416 is included so that cap 210 can engage cannula 202and be released from cannula 202. Instrument guide clip 418 is includedto allow the instrument guide 204 to be held against the cap 210 androtate against a top face of the cap 210, and to be resiliently bentaway from the instrument guide 204 in order to allow the instrumentguide 204 to be released from the cap 210. Thus by moving the lockingring 404, the cap 210 and instrument guide 204 combination can beremoved from the cannula 202, and by moving the instrument guide clip418, the instrument guide 204 can be removed from the cap 210 andcannula 202 combination.

In some embodiments, engagement . release mechanism 416 may be difficultto access when instrument guide 204 is installed. The inaccessibility ofengagement and release mechanism 416 can help to prevent unintentionalrelease of cap 210 from cannula 202, which would lead to loss ofinsufflation pressure. In some embodiments, it is therefore preferred toremove instrument guide 204 from cap 210 before removing cap 210 fromcannula 202.

FIGS. 4S and 4T illustrate a cannula 202 and coupling of cap 210 similarto that shown in FIGS. 4K through 4M to cannula 202. As shown in FIG.4S, cannula 202 includes a receiver 444 that can receive the latch tabs419 of engagement and release mechanism 416. Further, cannula 202includes pin receivers 446 that receive pins 426 of cap 210. In someembodiments, the keying feature relationship represented by pinreceivers 446 and receive pins 426 can be inverted, with projections ona cannula 202 and receptacles on the cap 210. Further, an insufflationconnector 442 can be included to receive insufflation gas from a hose,and seal 408 is shaped to allow gas to flow from connector 442 throughthe cannula and enter the surgical site (see e.g., FIG. 4U). As shown inFIG. 4T, cap 210 can be attached to cannula 202. Engagement and releasemechanism 416 couples cap 210 to cannula 210 in a releasable fashion. Asshown in FIG. 4T, clip 418 can align with latch feature 212 on thecannula 202 to create a streamlined perimeter of the assembly. As shownin FIG. 4T, seal 408 resides in cannula bowl 448 of cannula 202.

FIGS. 4U and 4V illustrate a cross section of cannula 202 and cap 210.As shown in FIG. 4U, seal 408 inserts into cannula bowl 448 when cap 210is latched to cannula 202's proximal end. In some embodiments, outerseal 436 seals against an inner wall of the cannula bowl to help preventinsufflation gas escape between the seal's outer wall and the cannulabowl's inner wall. As shown in FIG. 4V (rotated around the longitudinalaxis by about 45 degrees from FIG. 4U), energizing ribs 414 engage withthe inner wall of cannula bowl 448 to push slits 410 closed. Asdepicted, the distance between the outer surfaces of ribs on oppositesides of the seal is such that a slight friction fit exists between theribs and the cannula's inner surface.

Therefore, cap 210 snaps into cannula 202 and can provide a seal againstinsufflation gas escaping when an object is not inserted in cannula 202.Seal 408, which is a cross slit seal as discussed above, engages theinner diameter walls of cannula 202 so that energizing ribs 414 can helpforce slits 410 closed. Seal 408, in addition to providing a seal todevices inserted through cannula 202, can also provide a perimeter sealaround the top of cannula 202, for example with outer seal 436integrated with seal 408. The seal 408 has an outer diameter larger thanthe outer diameter of objects inserted through the seal 408. Therefore,as shown in FIGS. 4U and 4V, the seal is positioned in a proximal endcannula bowl 448, which has an inner diameter larger than the innerdiameter of the cannula shaft. The bowl 448 allows the seal 408 to bepositioned in the cannula 202 and to flex open while the relativelysmaller cannula shaft diameter allows for the minimum possible patientincision length. Further, cap 210 can be mechanically keyed to cannula210 by engagement mechanism 416 in order to ensure the correct cap 210and cannula 202 pair is mated and/or ensure the cap 210 is correctlyoriented on the cannula 202. Skilled artisans will understand that manypossible alternate mechanical configurations may be used to attach thecap 210 to the cannula 202 (e.g., various snaps, bayonet-type orscrew-type mounts, locking levers, friction fit configurations, etc.).The embodiments described herein are advantageous for their low heightand easy operation by operating room personnel with gloved hands in thetight space between the robotic manipulator and the patient, but othermechanisms can also be used.

Cannula seal 408 also can seal against devices that are inserted throughcap 210 in order to prevent insufflation gas from escaping when objectsare inserted through the seal. As is illustrated in FIG. 2B, channelportion 208 of instrument guide 204 is inserted through slits 410 ofseal 408, and instrument guide 204 can engage lid 402 of cap 210. Seal408, then, can seal around channel portion 208 with integrated innerseals 434 (FIGS. 4L, 4N). Therefore, when channel portion 208 is notpresent, energizing ribs 414 force slits 410 closed. When channelportion 208 is inserted through slits 410, inner seals 434 seal againstchannel portion 208. As illustrated in FIGS. 3A and 3B, seal 408 canalso seal against an obturator 302 inserted through cap 210. Otherdevices may be inserted through the seal into the cannula as well.

Seal 408 seals around the inner circumference of cannula 202 to sealcannula bowl 448. As discussed above, some embodiments of seal 408, forexample as illustrated in FIGS. 4B-4E, can have a relatively high aspectratio (i.e., ratio between the height and the slit length), requiring along cannula bowl 448, while some embodiments of seal 408, for exampleas illustrated in FIGS. 4F-4O, can have a low aspect ratio, allowing ashorter cannula bowl 448. Embodiments of seal 408 can have any of thefeatures illustrated in FIGS. 4B-4D. The advantages of the relativelyshorter cannula bowl are described elsewhere in this description.

Seal 408 can be formed of any suitably resilient material. For example,seal 408 can be formed of an elastomer material such as silicone, inwhich the stiffness of the material can be controlled during production.In some embodiments, a parylene coating can be used on seal 408 toreduce friction. Reducing friction can help to prevent seal inversionupon removal of an inserted instrument,

As discussed above, using a soft material for seal 408 can facilitatesealing of slits 410 and works well for seal embodiments with a highaspect ratio. Using a stiffer material helps to keep the shape of seal408, especially in embodiments with low aspect ratios, and may preventseal 408 from seal inversion as an inserted device is withdrawn.However, a stiffer material can also reduce the tendency of slits 410 toclose and seal. Therefore, the stiffness of the material used to formseal 408 balances the competing concerns of providing a good seal withthe ability to keep a shape.

As described above, ribs 414 force slits 410 closed so that seal 408seals against insufflation gas escaping. Ribs 414 are helpful forclosing cross slits 410 of seals 408, which extend into cannula 210, inembodiments of seals 408 formed of stiffer materials. As discussedabove, a stiffer material may be used where the width of seal 408 isrelatively large compared to the height of seal 408. Ribs 414 increasethe effective sealing of cross slits 410 if a stiffer material is used.

Instrument Guide and Seal

In addition to cap 210 being coupled to cannula 202, as described above,instrument guide 204 is coupled to cap 210 so that instrument guide 204,cap 210, and cannula 202 form port 100. FIG. 5A illustrates a crosssection of instrument guide 204 engaged with cap 210. As shown, clip 418allows instrument guide 204 to be mechanically and removably fastened tocap 210. As shown in FIG. 5A, channel portion 208 is inserted throughcap 210, A portion of seal 408, seal 434 that as described above sealsaround channel portion 208, is illustrated in FIG. 5A.

Funnel portion 206 of instrument guide 204 includes lower part 504 andupper part 506. Lower part 504 can be integrally formed (formed as asingle piece) with channel portion 208, as shown in FIG. 5B, or it canbe separately formed, Upper part 506 engages and can be snapped intolower part 504 during manufacturing.

As described above, when a cannula 210 is inserted into the body andinsufflation gas introduced at the surgical site, the gas is preventedfrom escaping through the empty cannula 210 by one seal feature (thecross slits 410), and the gas is prevented from escaping between thecannula's inner wall and an inserted object by another seal feature (thewipe- or septum-type seal 434 in some embodiments). But since theinstrument guide 204 has instrument channels that allow instruments toreach inside the patient, additional seals are needed to preventinsufflation gas from escaping through the instrument channels. And soin the instrument guide, one seal feature prevents the gas from escapingthrough a channel when no instrument is inserted, and another sealfeature prevents gas from escaping between the channel's inner wall andthe instrument when an instrument is inserted in the channel.

As shown in FIGS. 5A and 5B, an instrument seal 520 is captured betweenupper part 506 and lower part 504. Instrument seal 520 engages withdoors 510 and 512, which open when an instrument 516 is inserted throughfunnel portion 206 into channel portion 208. In some embodiments, doors512 and 510 can be mechanically opened, for example door 512 can beopened with an actuator 514, so that an operator can independentlyoperate door 512. Instrument seal 520 seals against doors 512 and 510when no instrument 516 is in place and seals against instrument 516 wheninstrument 516 is inserted.

Each of the openings in seal 520 is sized and shaped to accommodate anassociated instrument outer diameter, and the corresponding door issized and shaped to seal against the opening. As is illustrated in FIG.5A, door 510 is a larger door than is door 512. In many applications, arelatively larger outer diameter camera instrument may be insertedthrough door 510 and relatively smaller outer diameter surgicalinstruments 516 are each inserted through one of doors 512.

Seal 408, discussed above, and seal 520 can be formed of any sealingmaterial, including silicone or other substances. Further, seals 408 and520 can be of any suitable stiffness. In some embodiments, seals 408 and520 can be coated with a lubricant, for example parylene, to reducefriction.

As shown in FIG. 5A, in some embodiments instrument seal 520 can be apyramidal-shaped seal where doors 510 and 512 engage seal 520 at anangle. Doors 510 and 512, therefore, can open and close by following alow arc that utilizes less lengthwise space in lower part 504. Further,the sealing area between doors 510 and 512 and seal 520 can besignificantly increased by the angled aspect of instrument seal 520,which may result in more effective sealing.

As shown in FIG. 5A, upper part 506 of funnel portion 206 includesfunnel guides 530 and 222 that receive instruments such as instrument516. Funnel guide 530, which is one of funnel guides 224, 226, or 228illustrated in FIG. 2C, guides instruments to one of doors 512. Funnelguide 222 guides instruments, usually an endoscope, to door 510. Asshown in FIG. 5A, funnel guide 530 can include a concave surface 532that captures the tip of an instrument 516. Concave surface 532transitions to a convex surface 522, which guides instrument 516 throughdoor 512 and into a corresponding channel 524 of channel portion 208.Funnel guide 222 is shaped similarly to funnel guide 530. The center 526of upper section 506 is raised above the outside edge 528 of upper part506, creating a convex shape to the top of upper part 506, This convexshape increases the effective size of the opening of funnel guide 530,making it easier to aim instrument 516 into the correct channel, channel524, of channel portion 208 during instrument loading.

As discussed above, seal 408 seals against insufflation gas loss alongthe outer diameter of channel portion 208. Seal 520 seals either againstdoors 512 and 510 or against an instrument, such as instrument 516illustrated in FIG. 5A. Therefore, access port 100 is substantiallysealed to prevent insufflation gas pressure loss at the surgical site asan instrument guide or other object is inserted or removed from thecannula and as one or more instruments or other objects are inserted orremoved from the instrument guide.

FIG. 5B is an exploded perspective view that illustrates an embodimentof instrument guide 204. As shown in FIG. 5B, lower part 504 can beintegrally formed with channel portion 208. Doors 510 and 512 and levers514 can be inserted and mechanically coupled in lower part 504. As isfurther shown in FIG. 5B, doors 510 and 512 may be spring loaded andbiased to the closed position against seal 520 with springs 536 and 538,respectively. Further, levers 514 may be sealed from the insufflationgas by O-rings 548, Seal 520 can be seated appropriately into lower part504, and upper part 506 can then be inserted and fixed into placeagainst lower part 504. An O-ring 534 can seal between upper part 506and lower part 504.

FIG. 5C illustrates an assembled instrument guide 204 as illustrated inFIG. 5B. FIG. 5C illustrates the convex nature of center walls 526 ofupper part 506, which help guide instrument tips into the correctindividual instrument guide channels during instrument insertion.Further, FIG. 5C illustrates multiple levers 514, one for each of doors510 and 512 (not shown).

FIG. 5D illustrates a cross sectional view along the A-A direction ofinstrument guide 204 as illustrated in FIG. 5C. FIG. 5D illustratesdoors 510 and 512 seated against seal 520. Further, FIG. 5D illustratesO-ring 534 between lower part 504 and upper part 506.

FIG. 5E illustrate a cross section along the B-B direction of instrumentguide 204 as illustrated in FIG. 5C. FIG. 5E illustrates mechanicalconnection 550 between levers 514 and doors 510 and 512, as well asmounts 552 that receive and support doors 510 and 512 in lower part 504.

FIGS. 6A and 6B are two illustrative cross sections of channel portion208. Channel portion 208 is shown with four illustrative instrumentchannels 524 (more or fewer channels may be used in other embodiments).The channels 524 may also be termed lumens, and in some embodimentschannels 524 are not completely enclosed. The cross sections of each ofthe channels 524 are sized and shaped to provide adequate support for aninstrument shaft as the shaft is inserted through channel portion 208and to allow channel portion 208 to be formed by molding for easymanufacturing. As shown in FIG. 6A, channels 524 include a camerachannel 610 and three instrument channels 612. Camera channel 610 islarger and differently shaped than instrument channels 612 toaccommodate the individual camera instrument cross section. A similarmodification may be made to one or more of the instrument channels toaccommodate various instrument cross section sizes and shapes. In theembodiments of channel portion 208 illustrated in FIG. 6A, the crosssection of camera channel 610 is oblong and the cross sections ofinstrument channels 612 are circular to approximate the actual crosssections of the instruments. This arrangement may result in thick areas614 in channel portion 208, which may cause injection molding problems,such as sinks, voids, and distortions during production. In order toreduce injection molding problems, the individual channel cross sectionsare shaped to produce a more uniform wall thicknesses in channel portion208. FIG. 6B illustrates an alternate embodiment in which the camerachannel 610 cross section has a more extended oblong shape and theinstrument channel 612 cross sections have rounded triangular shapes.This design results in less thick areas 614, which improves injectionmolding results during manufacturing, while still supporting surgicaland camera instruments.

FIG. 7A is a top perspective view of an embodiment of seal 520, and FIG.7B is a bottom view of lower part 504. The embodiment of seal 520illustrated in FIG. 7A is a pyramid-shaped seal with openings 712 thatalign with and match the shapes of channels 524. As such, openings 712are shaped to accommodate the shapes of channels 524. As shown in FIG.7B, lower part 504 includes door 510 and doors 512 that seal againstopenings 712 in seal 520.

FIG. 7C illustrates a top view of an instrument seal 520. As is shown,openings 712 include a large opening appropriate for a camera channel610 and three small openings appropriate for instrument channels 612.Lips 720 around openings 712 can seal around the shafts of instruments516 and can provide a seat to seal against doors 510 and 512. In someembodiments, as discussed further below, seal 520 can include two partsthat respectively seal against doors 510 and 512 and the shaft of aninstrument 516.

FIGS. 7D and 7E show cross sections of an embodiment of instrument seal520 along the directions A-A and B-B shown in FIG. 7C, respectively.FIGS. 7D and 7E illustrate how in some embodiments the openings 712 areformed in flat faces of the seal's general pyramid shape. It can be seenthat each opening is sized and shaped to seal against an instrumentinserted through the opening. For example, if an instrument shaft has acircular cross section, then the corresponding opening 712 is shaped asan ellipse in a plane that bisects the instrument shaft at the angle ofthe pyramid face to the instrument shaft axis. Therefore, as illustratedin FIG. 7C, the opening 712 appears circular when viewed alonginstrument shaft axis, and the lip of the opening seals against theinstrument shaft. The elliptical opening shape is useful for cylindricalinstruments that roll around the instrument shaft axis. It should beunderstood that although several seal 520 embodiments are described asgenerally pyramid-shaped, other shapes may be used. For example, aconcave dome shape or other concave shape may be used, and the openings712 are formed in a continuously curving surface.

FIGS. 7F and 7G illustrates top and bottom perspective views of anembodiment of instrument seal 520 and further illustrate the generalpyramid shape. As is further illustrated, an outer lip 722 can sealbetween the instrument guide's lower part 504 and upper part 506 so thata seal is established between the instrument guide and the seal 520body. Structures 724 and 726 can help position and align instrument seal520 between lower part 504 and upper part 506 so that openings 712 areappropriately positioned.

FIGS. 7H and 7I illustrate another embodiment of a single-pieceinstrument seal 520. Instrument seal 520 as illustrated in FIGS. 7Cthrough 7G is pyramid shaped and, as discussed above, is positionedbetween lower part 504 and upper part 506. As illustrated in FIG. 7I,seal 520 does not include lips 720 around openings 712 that seal againstthe shaft of an instrument. Instead, a door seal 738 seals against doors510 and 512 that are positioned in lower port 504 and further is sizedto seal against the shaft of an inserted instrument.

In the instrument seal 520 embodiments described so far, each opening isused to both seal against an instrument shaft and to provide a seatagainst which a door seals. In other embodiments, separate alignedopenings may be used so that one opening seals against the instrumentshaft and another opening provides the seat for the door. The separateopening may be formed in two different pieces, or they may be formed ina single piece.

FIGS. 7I and 7K illustrate another embodiment of seal 520. Theembodiment of seal 520 illustrated in FIG. 7J includes two parts: a doorseal 730 and a shaft seal 732. Door seal 730 is a flat lip seal that ispositioned between the instrument guide's lower part 504 and upper part506, as discussed above. Door seal 730 then seals against doors 510 and512 as discussed above. Shaft seal 732 is positioned in the instrumentguide's lower part 504 to seal against the shaft of an instrument.

FIG. 7K illustrates a cross section of an embodiment of seal 520. Asshown in FIG. 7K, openings 712 a of door seal 730 and openings 712 b ofshaft seal 732 are aligned so that instruments pass through door seal730 and shaft seal 732 seals against the shaft of the instrument. Eachopening 712 a is sized and shaped to seal against a corresponding door(not shown). Openings 712 b of shaft seal 732 are sized and shapedappropriately to seal against the shaft of the instrument. Asillustrated in FIG. 7J, protrusions 734 molded into door seal 730 can beused to position and align door seal 730 in instrument guide 204.Structure 736 in shaft seal 732 can be used to position and align shaftseal 732 in instrument guide 204.

FIGS. 7L and 7M illustrate another embodiment of seal 520, Theembodiment of seal 520 illustrated in FIG. 7L includes two parts: a doorseal 730 and a shaft seal 732, In the embodiment illustrated 7L, doorseal 730 is a pyramid seal similar to that shown in FIGS. 7A through 7I.Shaft seal 732 is a flat lip seal that engages the shaft of aninstrument. As discussed above, door seal 730 is positioned between theinstrument guide's lower part 504 and upper part 506 and seals againstdoor 510 and doors 512, as discussed above. Shaft seal 732 is positionedin the instrument guide's lower part 504 to seal against the shaft of aninstrument. Openings 712 b of shaft seal 732 are sized appropriately toseal against the shaft of the instrument. It can be seen that an opening712 a in door seal 730 may also be sized and shaped to seal against aninstrument shaft so that two openings 712 a and 712 b provide a sealagainst an instrument shaft and one of the two openings 712 a providesthe seal against the door.

FIG. 7M illustrates a cross section of the embodiment of seal 520illustrated in FIG. 7L. Door seal 730 and shaft seal 732 are positionedrelative to one another such that openings 712 a and 712 b are alignedwith each other and with channels 610 and 612.

FIGS. 7N and 7O illustrate a single-piece embodiment of instrument seal520 that incorporates separate door and instrument shaft seal aspects.Instrument seal 520 as illustrated in FIGS. 7N and 7O is pyramid shaped,although other shapes may be used, as discussed above. As discussedabove, instrument seal 520 is positioned between the instrument guide'slower part 504 and upper part 506. As illustrated in FIG. 7O, seal 520includes a door seal part 734 and an instrument shaft seal part 736associated with each instrument channel in the instrument guide. Thedoor seal part 734 includes openings 712 a and seals against door 510and doors 512 that are positioned in the instrument guide's lower part504. The instrument shaft seal part 736 includes openings 712 b andseals against the shafts of inserted instruments. FIGS. 7N and 7Ofurther illustrate that in double seal embodiments the door seals may bepositioned distally of the shaft seals, as with the single sealembodiments illustrated in FIGS. 7A and 7C-7G, and in contrast withpreviously described double seal embodiments in which the door seals arepositioned proximally of the shaft seals.

Referring again to FIG. 7B, door 510 can be larger than doors 512 inorder to accommodate a camera instrument, which is typically larger thana tissue manipulation instrument, or other specially sized instrument.As illustrated in FIGS. 7A and 7B, seal 520 seals against door 510 anddoors 512, which are spring loaded to seat against the seal 520openings. Further, seal 520 seals against instruments that are insertedthrough openings 712. As is further illustrated in FIG. 7B, theinstrument guide's lower part 504 includes levers 514 that allow anoperator to open each of door 510 and doors 512. An operator can thenmanually open any of door 510 or doors 512 to allow for insertion of aninstrument, or hold open any of door 510 or doors 512 open to allow aninstrument to be removed through one of openings 712.

In some embodiments, levers 514 are not directly affected by opening ofdoor 510 or doors 512. In such embodiments, levers 514 are not rigidlykeyed to the movement of doors 510 and 512, so that if a door 510, 512opens, the corresponding lever does not move. Therefore, doors 510 and512 do not fight the friction of activating levers 514 (e.g., frictionfrom O-rings around the levers). Additionally, because levers 514 do notmove when doors 510 and 512 open, it is less likely that any of doors510 and 512 might get jammed or broken because an lever 514 becomeslimited in motion as an instrument, such as instrument 516, is beinginstalled.

FIGS. 8A-8D illustrate operation of a door mechanism 802 according tosome embodiments of the present invention. The door mechanism 802 shownin FIG. 8A can be one of doors 510 and 512. As shown in FIG. 8A, doormechanism 802 includes a sealing part 804 that engages against lip 720of seal 520, a body part 806 that forms sealing part 804, a pivot part810, and an arm 808 that connects pivot part 810 with body part 806.Lever 514 is linked to arm 808 as described in more detail below. FIG.8A illustrates door mechanism 802 in a closed position against seal 520.FIG. 8B illustrates opening of door mechanism 802 through insertion ofan instrument (not shown). As shown in FIG. 8B, the instrument pushesdoor mechanism 802 open while lever 514 remains stationary. Sinceinserting an instrument moves arm 808 but does not move lever 514, theforce required to insert an instrument is only enough to counteract arm808's torque against seal 520, and so instrument insertion is madeeasier.

FIGS. 8C and 8D illustrate opening of door 802 with lever 514. As shownin FIG. 8D, lever 514 is mechanically coupled to engage door mechanism802 at pivot 810. As such, lever 514 and door mechanism 802 include acommon pivot axis. The mating configuration allows door mechanism 802 toswing open without activating or otherwise affecting lever 514 as shownin FIG. 8B. However, if lever 514 is rotated, door mechanism 802 isengaged at pivot 810, and door mechanism 802 is opened. As shown in FIG.8D, pivot 810 includes a center shaft 812 that is mechanically connectedto door 802. A dog 814 is connected to center shaft 812 such that it canengage with lever 514 during certain rotations of lever 514. If pivot810 is rotated to open door 802, dog 814 may not engage lever 514.However, if lever 514 is rotated to open door 802, dog 814 is engagedwith lever 514. Therefore, pivot 810 of door mechanism 802 can rotateopen without contacting lever 514. However, rotating lever 514 engagesdoor mechanism 802 at pivot 810 to open door mechanism 802. it can beseen that by altering the engagement angles between the door and thelever, when an instrument is inserted and holding a door open, the levercan cause a small additional rotation to the door to completelydisengage the arm 808 from the instrument shaft.

FIGS. 9A and 9B illustrate the relationship between seal angle andopening angle of a door mechanism 802 according to some embodiments ofthe present invention. FIG. 9A illustrates an embodiment of doormechanism 802 where seal 520 is perpendicular with respect to channel524, for example, a seal 520 similar to that shown in FIGS. 7H and 7I.FIG. 9C illustrates an embodiment of door mechanism 802 as shown in FIG.9A with door mechanism 802 closed. As illustrated in FIG. 9A, for atypical sized instrument channel 524, the opening angle of doormechanism 802 can be very large when an instrument such as surgicalinstrument 516 is inserted. In some cases, the opening angle can be60-90°. Such a large angle results in a particularly large verticalthrow (height) of sealing surface 804 and results in a large spaceneeded to accommodate door 802 in lower part 504 above channel 524. FIG.9B illustrates embodiments in which seal 520 has angled openings 712with respect to channel 524. FIG. 9D illustrates an embodiment of doormechanism 802 as shown in FIG. 9B with door mechanism 802 in a closedposition. In this particular example, the opening angle of doormechanism 802 can be very much smaller, in some cases as low as 20-25°.A smaller angle results in a smaller throw (height) of sealing surface804, which can be accommodated in a much smaller space in lower part 504above channel 524. Embodiments of door mechanism 802 according to thepresent invention can accommodate any seal angle. The height illustratedin FIG. 9A corresponds with an additional length of an instrument 516.The shorter height of the embodiment of FIG. 9B allow for a reducedlength of an instrument 516. Also, with the small angle a smaller springdeflection at pivot 810 can be realized.

In some situations, the relationship between the configuration of thedoor and the configuration of an instrument end effector is considered.FIG. 10A illustrates a door mechanism 802 as shown in FIG. 9C that sealswith sealing surface 804 against a flat seal 520 similar to that shownin FIGS. 7J and 7K. As shown in FIG. 10A, an instrument 516 illustratedas a cautery hook instrument is being removed through seal 802 If thecautery hook end effector engages against the door, however, body 806,arm 808, and pivot 810 of door mechanism 802 are arranged in a fashionthat allows the normal force F from the hook to provide a force thattends to close door mechanism 802, instead of to open door mechanism802.

FIG. 10B illustrates embodiments of door mechanism 802 as shown in FIG.9D, which is one of doors 510 and 512. As shown in FIG. 10B, instrument516 is a cautery hook instrument being removed through seal 520. Asshown in FIG. 10B, door mechanism 802 includes a sealing part 804 thatengages with seal 520, a body part 806 that forms sealing part 804, apivot part 810, and an arm 808 that connects pivot part 810 with bodypart 806, as described above. In door mechanism 802 illustrated in FIG.10B, the angled sealing surface 804 reduces the arc through which door802 swings in order to open and close. The shorter arc in addition to arounded backside of door mechanism 802 allows the door to be easilypushed out of the way during instrument withdrawal and not get caught oninstruments such as a cautery hook that is being removed from theinstrument guide 204. The shorter arc also means the torsion springslocated at pivot portion 810 go through less deflection, and so thespring force is more constant. As is illustrated in FIG. 10B, the normalforce F from the hook of instrument 516 is in a direction to push doormechanism 802 open (although frictional forces may still try to pulldoor closed and thereby snag instruments such as a cautery hook).

The above detailed description is provided to illustrate specificembodiments of the present invention and is not intended to be limiting.Numerous variations and modifications within the scope of the presentinvention are possible. The present invention is set forth in thefollowing claims.

1. An instrument guide assembly comprising: a cap comprising a movableclip; and an instrument guide comprising: a plurality of instrumentchannels extending through the instrument guide: and a first part theinstrument guide positionable to abut the cap such that the movable clipis positioned over the first part of the instrument guide and such thatthe first part of the instrument guide slides between the cap and themovable clip as the instrument guide rotates within the cap.
 2. Theinstrument guide assembly of claim 1, wherein: the cap comprises a seal;the seal is open on the condition that the instrument guide is insertedthrough the seal; and the seal is closed on the condition that theinstrument guide is not inserted through the seal.
 3. The instrumentguide assembly of claim 1, further a cannula configured to receive theinstrument guide; wherein the cap comprises a base couplable to thecannula.
 4. The instrument guide assembly of claim 3, wherein: the capcomprises a seal; the seal is open on the condition that the instrumentguide is inserted through the seal; and the seal is closed on thecondition that the instrument guide is not inserted through the seal. 5.The instrument guide assembly of claim 3, wherein: the movable clip ismovable to release instrument guide from the cap.
 6. The instrumentguide assembly of claim 3, wherein: the seal comprises a side wall andslits; the sidewall comprises folded sidewall panels that meet to formthe slits when the seal is in a closed position; and a height of thefolded sidewall panels is greater than a length of the slits.
 7. Theinstrument guide assembly of claim 3, wherein: the cap comprises a lid;the lid comprises the clip; and the cap comprises a locking ring that issized and shaped to engage the cannula.
 8. The instrument guide assemblyof claim 7, wherein: the locking ring comprises a release mechanism; andthe locking ring rotates against the release mechanism, the locking ringengaging the cannula when the locking ring is rotated.
 9. An instrumentguide assembly comprising: an instrument guide and a cap; the instrumentguide comprising a first portion and a plurality of instrument channelsextending through the instrument guide, each instrument channel of theplurality of instrument channels configured to receive a surgicalinstrument shaft; and the cap comprising a lid, a cannula locking ring,and a cannula seal assembly between the lid and the locking ring; thelid comprising an instrument guide clip, engagement of the clip with thefirst portion of the instrument guide releasably securing the instrumentguide to the cap and allowing rotation of instrument guide with respectto the cap when the clip is engaged with the first portion of theinstrument guide; the cannula locking ring releasably securing the capto a cannula; and the cannula seal assembly sealing against theinstrument guide when the instrument guide is inserted through thecannula seal assembly and sealing against itself when the instrumentguide is not inserted through the cannula seal assembly.
 10. Theinstrument guide assembly of claim 9, wherein: the locking ringcomprises a release mechanism releasably engageable with the cannula toreleasably secure the cap to the cannula.
 11. The instrument guideassembly of claim 10, wherein: the release mechanism comprises aplurality of latching tabs engageable with the cannula.
 12. Theinstrument guide assembly of claim 9, wherein: the seal comprises a sidewall and slits; the sidewall comprises folded sidewall panels that meetto form the slits when the seal is in a closed position; and a height ofthe folded sidewall panels is greater than length of the slits.
 13. Theinstrument guide assembly of claim 12, wherein: the cannula sealassembly comprises ribs formed in the side wall; the ribs are sized andshaped to engage an inside wall of the cannula; and engagement of theribs with the inside wall of the cannula biases the slits to a closedposition when the instrument guide is not inserted through the cannulaseal assembly.
 14. The instrument guide assembly of claim 13, wherein:the ribs are formed in the side wall at ends of the slits; and the ribsare sized and shaped to bias the slits toward a closed position when theribs are engaged with the inside wall of the cannula.
 15. The instrumentguide assembly of claim 9, wherein: the cannula seal assembly comprisesa first portion that engages the lid.
 16. The instrument guide assemblyof claim 9, wherein: a first part the instrument guide is positionableto abut the cap such that the movable clip is positioned over the firstpart of the instrument guide and such that the first part of theinstrument guide slides between the cap and the movable clip as theinstrument guide rotates within the cap.
 17. The instrument guideassembly of claim 9, wherein: the cannula seal assembly comprises adiaphragm seal configured to seal against the instrument guide.
 18. Theinstrument guide assembly of claim 17, wherein: the cannula sealassembly comprises an outer seal configured to seal against an innerwall of a cannula.
 19. The instrument guide assembly of claim 9,wherein: the cap comprises a base coupled to the lid; and the lockingring and the cannula seal are between the lid and the base.